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From:   Tedd Ho-Jeong An <hj.tedd.an@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     Tedd Ho-Jeong An <tedd.an@intel.com>
Subject: [RFC PATCH V5] Bluetooth: vhci: Add support creating extended device mode
Date:   Mon,  8 Nov 2021 19:13:43 -0800
Message-Id: <20211109031343.87728-1-hj.tedd.an@gmail.com>
MIME-Version: 1.0
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From: Tedd Ho-Jeong An <tedd.an@intel.com>

This patch adds new opcode(0x03) for HCI Vendor packet to support
creating extended device mode. In order to avoid the conflict with the
legacy opcode, it has to be 0x03 only and all other bits must be set to
zero.

Then, it is followed by the extended configuration data that contains
the device type and the flags to be used.

Signed-off-by: Tedd Ho-Jeong An <tedd.an@intel.com>
---
 drivers/bluetooth/hci_vhci.c | 200 ++++++++++++++++++++++++++++-------
 1 file changed, 162 insertions(+), 38 deletions(-)

diff --git a/drivers/bluetooth/hci_vhci.c b/drivers/bluetooth/hci_vhci.c
index 49ac884d996e..4c0cfb29c0e8 100644
--- a/drivers/bluetooth/hci_vhci.c
+++ b/drivers/bluetooth/hci_vhci.c
@@ -30,6 +30,24 @@
 
 static bool amp;
 
+/* This is the struct for extended device configuration.
+ * The opcode 0x03 is used for creating an extended device and followed by
+ * the configuration data below.
+ * dev_type is Primay or AMP.
+ * flag_len is the length of flag array
+ * flag array contains the flag to use/set while creating the device.
+ */
+struct vhci_ext_config {
+	__u8	dev_type;
+	__u8	flag_len;
+	__u8	flags[0];
+};
+
+#define VHCI_EXT_FLAG_ENABLE_AOSP		0x01
+#define VHCI_EXT_FLAG_QUIRK_RAW_DEVICE		0x02
+#define VHCI_EXT_FLAG_QUIARK_EXTERNAL_CONFIG	0x03
+#define VHCI_EXT_FLAG_QUIRK_INVALID_BDADDR	0x04
+
 struct vhci_data {
 	struct hci_dev *hdev;
 
@@ -278,11 +296,52 @@ static int vhci_setup(struct hci_dev *hdev)
 	return 0;
 }
 
+static int vhci_register_hdev(struct hci_dev *hdev, __u8 opcode)
+{
+	struct vhci_data *data = hci_get_drvdata(hdev);
+	struct sk_buff *skb;
+
+	skb = bt_skb_alloc(4, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	if (hci_register_dev(hdev) < 0) {
+		BT_ERR("Can't register HCI device");
+		kfree_skb(skb);
+		return -EBUSY;
+	}
+
+	debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
+			    &force_suspend_fops);
+
+	debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
+			    &force_wakeup_fops);
+
+	if (IS_ENABLED(CONFIG_BT_MSFTEXT))
+		debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
+				    &msft_opcode_fops);
+
+	if (IS_ENABLED(CONFIG_BT_AOSPEXT))
+		debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
+				    &aosp_capable_fops);
+
+	hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
+
+	skb_put_u8(skb, 0xff);
+	skb_put_u8(skb, opcode);
+	put_unaligned_le16(hdev->id, skb_put(skb, 2));
+	skb_queue_tail(&data->readq, skb);
+
+	wake_up_interruptible(&data->read_wait);
+
+	return 0;
+}
+
 static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
 {
 	struct hci_dev *hdev;
-	struct sk_buff *skb;
 	__u8 dev_type;
+	int ret;
 
 	if (data->hdev)
 		return -EBADFD;
@@ -297,15 +356,9 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
 	if (opcode & 0x3c)
 		return -EINVAL;
 
-	skb = bt_skb_alloc(4, GFP_KERNEL);
-	if (!skb)
-		return -ENOMEM;
-
 	hdev = hci_alloc_dev();
-	if (!hdev) {
-		kfree_skb(skb);
+	if (!hdev)
 		return -ENOMEM;
-	}
 
 	data->hdev = hdev;
 
@@ -331,45 +384,108 @@ static int __vhci_create_device(struct vhci_data *data, __u8 opcode)
 	if (opcode & 0x80)
 		set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
 
-	if (hci_register_dev(hdev) < 0) {
-		BT_ERR("Can't register HCI device");
+	/* Legacy method returns opcode instead of dev type */
+	ret = vhci_register_hdev(hdev, opcode);
+	if (ret < 0) {
 		hci_free_dev(hdev);
 		data->hdev = NULL;
-		kfree_skb(skb);
-		return -EBUSY;
 	}
 
-	debugfs_create_file("force_suspend", 0644, hdev->debugfs, data,
-			    &force_suspend_fops);
+	return ret;
+}
 
-	debugfs_create_file("force_wakeup", 0644, hdev->debugfs, data,
-			    &force_wakeup_fops);
+static int vhci_create_device(struct vhci_data *data, __u8 opcode)
+{
+	int err;
 
-	if (IS_ENABLED(CONFIG_BT_MSFTEXT))
-		debugfs_create_file("msft_opcode", 0644, hdev->debugfs, data,
-				    &msft_opcode_fops);
+	mutex_lock(&data->open_mutex);
+	err = __vhci_create_device(data, opcode);
+	mutex_unlock(&data->open_mutex);
 
-	if (IS_ENABLED(CONFIG_BT_AOSPEXT))
-		debugfs_create_file("aosp_capable", 0644, hdev->debugfs, data,
-				    &aosp_capable_fops);
+	return err;
+}
 
-	hci_skb_pkt_type(skb) = HCI_VENDOR_PKT;
+static int __vhci_create_extended_device(struct vhci_data *data,
+							struct sk_buff *skb)
+{
+	struct hci_dev *hdev;
+	struct vhci_ext_config *config;
+	int i, ret;
+	__u8 flag;
 
-	skb_put_u8(skb, 0xff);
-	skb_put_u8(skb, opcode);
-	put_unaligned_le16(hdev->id, skb_put(skb, 2));
-	skb_queue_tail(&data->readq, skb);
+	if (data->hdev)
+		return -EBADFD;
 
-	wake_up_interruptible(&data->read_wait);
-	return 0;
+	/* Make sure the skb has a minimum valid length */
+	if (skb->len < sizeof(*config))
+		return -EINVAL;
+
+	config = (void *)(skb->data);
+	if (skb->len < sizeof(*config) + config->flag_len)
+		return -EINVAL;
+
+	if (config->dev_type != HCI_PRIMARY && config->dev_type != HCI_AMP)
+		return -EINVAL;
+
+	hdev = hci_alloc_dev();
+	if (!hdev)
+		return -ENOMEM;
+
+	data->hdev = hdev;
+
+	hdev->bus = HCI_VIRTUAL;
+	hdev->dev_type = config->dev_type;
+	hci_set_drvdata(hdev, data);
+
+	hdev->open  = vhci_open_dev;
+	hdev->close = vhci_close_dev;
+	hdev->flush = vhci_flush;
+	hdev->send  = vhci_send_frame;
+	hdev->get_data_path_id = vhci_get_data_path_id;
+	hdev->get_codec_config_data = vhci_get_codec_config_data;
+	hdev->wakeup = vhci_wakeup;
+	hdev->setup = vhci_setup;
+	set_bit(HCI_QUIRK_NON_PERSISTENT_SETUP, &hdev->quirks);
+
+	for (i = 0; i < config->flag_len; i++) {
+		flag = config->flags[i];
+		switch (flag) {
+		case VHCI_EXT_FLAG_ENABLE_AOSP:
+			data->aosp_capable = 1;
+			break;
+		case VHCI_EXT_FLAG_QUIRK_RAW_DEVICE:
+			set_bit(HCI_QUIRK_RAW_DEVICE, &hdev->quirks);
+			break;
+		case VHCI_EXT_FLAG_QUIARK_EXTERNAL_CONFIG:
+			set_bit(HCI_QUIRK_EXTERNAL_CONFIG, &hdev->quirks);
+			break;
+		case VHCI_EXT_FLAG_QUIRK_INVALID_BDADDR:
+			set_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks);
+			break;
+		default:
+			BT_ERR("Invalid flag");
+			hci_free_dev(hdev);
+			data->hdev = NULL;
+			return -EINVAL;
+		}
+	}
+
+	/* Extended method returns the fixed extension opcode 0x03 */
+	ret = vhci_register_hdev(hdev, 0x03);
+	if (ret < 0) {
+		hci_free_dev(hdev);
+		data->hdev = NULL;
+	}
+
+	return ret;
 }
 
-static int vhci_create_device(struct vhci_data *data, __u8 opcode)
+static int vhci_create_extended_device(struct vhci_data *data,
+							struct sk_buff *skb)
 {
 	int err;
-
 	mutex_lock(&data->open_mutex);
-	err = __vhci_create_device(data, opcode);
+	err = __vhci_create_extended_device(data, skb);
 	mutex_unlock(&data->open_mutex);
 
 	return err;
@@ -419,14 +535,22 @@ static inline ssize_t vhci_get_user(struct vhci_data *data,
 		opcode = *((__u8 *) skb->data);
 		skb_pull(skb, 1);
 
-		if (skb->len > 0) {
-			kfree_skb(skb);
-			return -EINVAL;
+		/* The dev_type 3 is used as an escape opcode for extension
+		 * handling. If dev_type is set to 3 all other bits must be
+		 * set to zero.
+		 */
+		if (opcode == 0x03) {
+			if (skb->len < 1)
+				ret = -EINVAL;
+			else
+				ret = vhci_create_extended_device(data, skb);
+		} else {
+			if (skb->len > 0)
+				ret = -EINVAL;
+			else
+				ret = vhci_create_device(data, opcode);
 		}
-
 		kfree_skb(skb);
-
-		ret = vhci_create_device(data, opcode);
 		break;
 
 	default:
-- 
2.25.1